1
2/*
3 * COMPILE WITH:
4 *      gcc -Wall gen_md5.c -o gen_md5
5 */
6
7
8/* taken from RFC-1321/Appendix A.3 */
9
10/*
11 * MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
12 */
13
14/*
15 * Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All rights
16 * reserved.
17 *
18 * License to copy and use this software is granted provided that it is
19 * identified as the "RSA Data Security, Inc. MD5 Message-Digest Algorithm"
20 * in all material mentioning or referencing this software or this function.
21 *
22 * License is also granted to make and use derivative works provided that such
23 * works are identified as "derived from the RSA Data Security, Inc. MD5
24 * Message-Digest Algorithm" in all material mentioning or referencing the
25 * derived work.
26 *
27 * RSA Data Security, Inc. makes no representations concerning either the
28 * merchantability of this software or the suitability of this software for
29 * any particular purpose. It is provided "as is" without express or implied
30 * warranty of any kind.
31 *
32 * These notices must be retained in any copies of any part of this
33 * documentation and/or software.
34 */
35
36#include <stdio.h>
37
38#include "md5.h"
39
40/*
41 * Constants for MD5Transform routine.
42 */
43#define S11 7
44#define S12 12
45#define S13 17
46#define S14 22
47#define S21 5
48#define S22 9
49#define S23 14
50#define S24 20
51#define S31 4
52#define S32 11
53#define S33 16
54#define S34 23
55#define S41 6
56#define S42 10
57#define S43 15
58#define S44 21
59
60static void MD5Transform(unsigned int[4], unsigned char[64]);
61static void Encode(unsigned char *, unsigned int*, unsigned int);
62static void Decode(unsigned int*, unsigned char *, unsigned int);
63static void MD5_memcpy(unsigned char *, unsigned char *, unsigned int);
64static void MD5_memset(char *, int, unsigned int);
65
66static unsigned char PADDING[64] =
67{
68    0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
69    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
70    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
71};
72
73/*
74 * F, G, H and I are basic MD5 functions.
75 */
76/* #define F(x, y, z) (((x) & (y)) | ((~x) & (z))) */
77#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
78#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
79#define H(x, y, z) ((x) ^ (y) ^ (z))
80#define I(x, y, z) ((y) ^ ((x) | (~z)))
81
82/*
83 * ROTATE_LEFT rotates x left n bits.
84 */
85#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
86
87/*
88 * FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4. Rotation is
89 * separate from addition to prevent recomputation.
90 */
91#define FF(a, b, c, d, x, s, ac) { (a) += F ((b), (c), (d)) + (x) + (unsigned int)(ac);  (a) = ROTATE_LEFT ((a), (s));  (a) += (b);   }
92#define GG(a, b, c, d, x, s, ac) {  (a) += G ((b), (c), (d)) + (x) + (unsigned int)(ac);  (a) = ROTATE_LEFT ((a), (s));  (a) += (b);   }
93#define HH(a, b, c, d, x, s, ac) {  (a) += H ((b), (c), (d)) + (x) + (unsigned int)(ac);  (a) = ROTATE_LEFT ((a), (s));  (a) += (b);   }
94#define II(a, b, c, d, x, s, ac) {  (a) += I ((b), (c), (d)) + (x) + (unsigned int)(ac);  (a) = ROTATE_LEFT ((a), (s));  (a) += (b);   }
95
96/*
97 * MD5 initialization. Begins an MD5 operation, writing a new context.
98 */
99void
100MD5Init(MD5_CTX * context)
101{
102    context->count[0] = context->count[1] = 0;
103    /*
104     * Load magic initialization constants.
105     */
106    context->state[0] = 0x67452301;
107    context->state[1] = 0xefcdab89;
108    context->state[2] = 0x98badcfe;
109    context->state[3] = 0x10325476;
110}
111
112/*
113 * MD5 block update operation. Continues an MD5 message-digest operation,
114 * processing another message block, and updating the context.
115 */
116void
117MD5Update(MD5_CTX * context, unsigned char *input, unsigned int inputLen)
118{
119    unsigned int i, index, partLen;
120
121    /* Compute number of bytes mod 64 */
122    index = (unsigned int) ((context->count[0] >> 3) & 0x3F);
123
124    /* Update number of bits */
125    if ((context->count[0] += ((unsigned int) inputLen << 3))
126	< ((unsigned int) inputLen << 3))
127	context->count[1]++;
128    context->count[1] += ((unsigned int) inputLen >> 29);
129
130    partLen = 64 - index;
131
132    /*
133     * Transform as many times as possible.
134     */
135    if (inputLen >= partLen) {
136	MD5_memcpy(&context->buffer[index], input, partLen);
137	MD5Transform(context->state, context->buffer);
138
139	for (i = partLen; i + 63 < inputLen; i += 64)
140	    MD5Transform(context->state, &input[i]);
141
142	index = 0;
143    } else
144	i = 0;
145
146    /* Buffer remaining input */
147    MD5_memcpy(&context->buffer[index], &input[i], inputLen - i);
148}
149
150/*
151 * MD5 finalization. Ends an MD5 message-digest operation, writing the the
152 * message digest and zeroizing the context.
153 */
154void
155MD5Final(unsigned char digest[16], MD5_CTX * context)
156{
157    unsigned char bits[8];
158    unsigned int index, padLen;
159
160    /* Save number of bits */
161    Encode(bits, context->count, 8);
162
163    /*
164     * Pad out to 56 mod 64.
165     */
166    index = (unsigned int) ((context->count[0] >> 3) & 0x3f);
167    padLen = (index < 56) ? (56 - index) : (120 - index);
168    MD5Update(context, PADDING, padLen);
169
170    /* Append length (before padding) */
171    MD5Update(context, bits, 8);
172    /* Store state in digest */
173    Encode(digest, context->state, 16);
174
175    /*
176     * Zeroize sensitive information.
177     */
178    MD5_memset((char *) context, 0, sizeof(*context));
179}
180
181/*
182 * MD5 basic transformation. Transforms state based on block.
183 */
184static void
185MD5Transform(unsigned int state[4], unsigned char block[64])
186{
187    unsigned int a = state[0], b = state[1], c = state[2], d = state[3], x[16];
188
189    Decode(x, block, 64);
190
191    /* Round 1 */
192    FF(a, b, c, d, x[0], S11, 0xd76aa478);	/* 1 */
193    FF(d, a, b, c, x[1], S12, 0xe8c7b756);	/* 2 */
194    FF(c, d, a, b, x[2], S13, 0x242070db);	/* 3 */
195    FF(b, c, d, a, x[3], S14, 0xc1bdceee);	/* 4 */
196    FF(a, b, c, d, x[4], S11, 0xf57c0faf);	/* 5 */
197    FF(d, a, b, c, x[5], S12, 0x4787c62a);	/* 6 */
198    FF(c, d, a, b, x[6], S13, 0xa8304613);	/* 7 */
199    FF(b, c, d, a, x[7], S14, 0xfd469501);	/* 8 */
200    FF(a, b, c, d, x[8], S11, 0x698098d8);	/* 9 */
201    FF(d, a, b, c, x[9], S12, 0x8b44f7af);	/* 10 */
202    FF(c, d, a, b, x[10], S13, 0xffff5bb1);	/* 11 */
203    FF(b, c, d, a, x[11], S14, 0x895cd7be);	/* 12 */
204    FF(a, b, c, d, x[12], S11, 0x6b901122);	/* 13 */
205    FF(d, a, b, c, x[13], S12, 0xfd987193);	/* 14 */
206    FF(c, d, a, b, x[14], S13, 0xa679438e);	/* 15 */
207    FF(b, c, d, a, x[15], S14, 0x49b40821);	/* 16 */
208
209    /* Round 2 */
210    GG(a, b, c, d, x[1], S21, 0xf61e2562);	/* 17 */
211    GG(d, a, b, c, x[6], S22, 0xc040b340);	/* 18 */
212    GG(c, d, a, b, x[11], S23, 0x265e5a51);	/* 19 */
213    GG(b, c, d, a, x[0], S24, 0xe9b6c7aa);	/* 20 */
214    GG(a, b, c, d, x[5], S21, 0xd62f105d);	/* 21 */
215    GG(d, a, b, c, x[10], S22, 0x2441453);	/* 22 */
216    GG(c, d, a, b, x[15], S23, 0xd8a1e681);	/* 23 */
217    GG(b, c, d, a, x[4], S24, 0xe7d3fbc8);	/* 24 */
218    GG(a, b, c, d, x[9], S21, 0x21e1cde6);	/* 25 */
219    GG(d, a, b, c, x[14], S22, 0xc33707d6);	/* 26 */
220    GG(c, d, a, b, x[3], S23, 0xf4d50d87);	/* 27 */
221    GG(b, c, d, a, x[8], S24, 0x455a14ed);	/* 28 */
222    GG(a, b, c, d, x[13], S21, 0xa9e3e905);	/* 29 */
223    GG(d, a, b, c, x[2], S22, 0xfcefa3f8);	/* 30 */
224    GG(c, d, a, b, x[7], S23, 0x676f02d9);	/* 31 */
225    GG(b, c, d, a, x[12], S24, 0x8d2a4c8a);	/* 32 */
226
227    /* Round 3 */
228    HH(a, b, c, d, x[5], S31, 0xfffa3942);	/* 33 */
229    HH(d, a, b, c, x[8], S32, 0x8771f681);	/* 34 */
230    HH(c, d, a, b, x[11], S33, 0x6d9d6122);	/* 35 */
231    HH(b, c, d, a, x[14], S34, 0xfde5380c);	/* 36 */
232    HH(a, b, c, d, x[1], S31, 0xa4beea44);	/* 37 */
233    HH(d, a, b, c, x[4], S32, 0x4bdecfa9);	/* 38 */
234    HH(c, d, a, b, x[7], S33, 0xf6bb4b60);	/* 39 */
235    HH(b, c, d, a, x[10], S34, 0xbebfbc70);	/* 40 */
236    HH(a, b, c, d, x[13], S31, 0x289b7ec6);	/* 41 */
237    HH(d, a, b, c, x[0], S32, 0xeaa127fa);	/* 42 */
238    HH(c, d, a, b, x[3], S33, 0xd4ef3085);	/* 43 */
239    HH(b, c, d, a, x[6], S34, 0x4881d05);	/* 44 */
240    HH(a, b, c, d, x[9], S31, 0xd9d4d039);	/* 45 */
241    HH(d, a, b, c, x[12], S32, 0xe6db99e5);	/* 46 */
242    HH(c, d, a, b, x[15], S33, 0x1fa27cf8);	/* 47 */
243    HH(b, c, d, a, x[2], S34, 0xc4ac5665);	/* 48 */
244
245    /* Round 4 */
246    II(a, b, c, d, x[0], S41, 0xf4292244);	/* 49 */
247    II(d, a, b, c, x[7], S42, 0x432aff97);	/* 50 */
248    II(c, d, a, b, x[14], S43, 0xab9423a7);	/* 51 */
249    II(b, c, d, a, x[5], S44, 0xfc93a039);	/* 52 */
250    II(a, b, c, d, x[12], S41, 0x655b59c3);	/* 53 */
251    II(d, a, b, c, x[3], S42, 0x8f0ccc92);	/* 54 */
252    II(c, d, a, b, x[10], S43, 0xffeff47d);	/* 55 */
253    II(b, c, d, a, x[1], S44, 0x85845dd1);	/* 56 */
254    II(a, b, c, d, x[8], S41, 0x6fa87e4f);	/* 57 */
255    II(d, a, b, c, x[15], S42, 0xfe2ce6e0);	/* 58 */
256    II(c, d, a, b, x[6], S43, 0xa3014314);	/* 59 */
257    II(b, c, d, a, x[13], S44, 0x4e0811a1);	/* 60 */
258    II(a, b, c, d, x[4], S41, 0xf7537e82);	/* 61 */
259    II(d, a, b, c, x[11], S42, 0xbd3af235);	/* 62 */
260    II(c, d, a, b, x[2], S43, 0x2ad7d2bb);	/* 63 */
261    II(b, c, d, a, x[9], S44, 0xeb86d391);	/* 64 */
262
263    state[0] += a;
264    state[1] += b;
265    state[2] += c;
266    state[3] += d;
267
268    /*
269     * Zeroize sensitive information.
270     */
271    MD5_memset((char *) x, 0, sizeof(x));
272}
273
274/*
275 * Encodes input (unsigned int) into output (unsigned char). Assumes len is a
276 * multiple of 4.
277 */
278static void
279Encode(unsigned char *output, unsigned int * input, unsigned int len)
280{
281    unsigned int i, j;
282
283    for (i = 0, j = 0; j < len; i++, j += 4) {
284	output[j] = (unsigned char) (input[i] & 0xff);
285	output[j + 1] = (unsigned char) ((input[i] >> 8) & 0xff);
286	output[j + 2] = (unsigned char) ((input[i] >> 16) & 0xff);
287	output[j + 3] = (unsigned char) ((input[i] >> 24) & 0xff);
288    }
289}
290
291/*
292 * Decodes input (unsigned char) into output (unsigned int). Assumes len is a
293 * multiple of 4.
294 */
295static void
296Decode(unsigned int * output, unsigned char *input, unsigned int len)
297{
298    unsigned int i, j;
299
300    for (i = 0, j = 0; j < len; i++, j += 4)
301	output[i] = ((unsigned int) input[j]) | (((unsigned int) input[j + 1]) << 8) |
302	    (((unsigned int) input[j + 2]) << 16) | (((unsigned int) input[j + 3]) << 24);
303}
304
305/*
306 * Note: Replace "for loop" with standard memcpy if possible.
307 */
308
309static void
310MD5_memcpy(unsigned char *output, unsigned char *input, unsigned int len)
311{
312    unsigned int i;
313    for (i = 0; i < len; i++)
314	output[i] = input[i];
315}
316
317/*
318 * Note: Replace "for loop" with standard memset if possible.
319 */
320static void
321MD5_memset(char *output, int value, unsigned int len)
322{
323    unsigned int i;
324    for (i = 0; i < len; i++)
325	output[i] = (char) value;
326}
327
328/*
329static void
330MDString(char *string, size_t len)
331{
332    MD5_CTX context;
333    unsigned char digest[16];
334    MD5Init(&context);
335    MD5Update(&context, string, len);
336    MD5Final(digest, &context);
337    printf("%s\t", string);
338    MDPrint(digest);
339    printf("\n");
340}
341*/
342/*
343static void
344MDPrint(unsigned char digest[16])
345{
346    unsigned int i;
347    for (i = 0; i < 16; i++)
348	/ printf("%02x", digest[i]); *
349	printf("%c", digest[i]);
350}
351*/
352
353